1. Dental School, University of Manchester, Manchester, UK;
2. Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Rikshospitalet, Oslo, Norway;
3. Copenhagen Cleft Palate Center, University Hospital of Copenhagen, Copenhagen, Denmark;
4. Cleft Palate and Craniofacial Center, Helsinki University Central Hospital, Helsinki, Finland;
5. Division of Surgery and Clinical Neuroscience, Oslo University Hospital, Oslo, Norway;
6. Department of Plastic Surgery, Sahlgrenska Academy, University of Gothenburg, Sweden;
7. Maxillofacial Unit, University Hospital, Linköping, Sweden;
8. Royal Belfast Hospital for Sick Children, Belfast, Northern Ireland, UK;
9. Center for Cleft Lip and Palate, Haukeland University Hospital, Bergen, Norway;
10. Department of Plastic and Reconstructive Surgery, Oslo University of Hospital Rikshospitalet, and Statped, Sørøst, Oslo, Norway